http://www.alternet.org/waroniraq/48846/According to U.S. Military Theory, We Can't Win in IraqBush's new top commander in Iraq says he thinks the war in Iraq is winnable, but his recent manual on counterinsurgency suggests otherwise. snip
During the Algerian war of independence between 1954 and 1962, French leaders decided to permit torture against suspected insurgents. Though they were aware that it was against the law and morality of war, they argued that:
This was a new form of war and these rules did not apply.
The threat the enemy represented, communism, was a great evil that justified extraordinary means.
The application of torture against insurgents was measured and nongratuitous.
This official condoning of torture on the part of French Army leadership had several negative consequences. It empowered the moral legitimacy of the opposition, undermined the French moral legitimacy, and caused internal fragmentation among serving officers that led to an unsuccessful coup attempt in 1962. In the end, failure to comply with moral and legal restrictions against torture severely undermined French efforts and contributed to their loss despite several significant military victories. ... France eventually recognized Algerian independence in July 1963. snip
The counterinsurgency Field Manual hints at an answer. It comes as the heading to the Algerian case study quoted above: "Lose Moral Legitimacy, Lose the War."
Petraeus the general still insists that the war can be won; Petraeus the theorist would seem to disagree.